The present invention relates to an apparatus and a method for information processing, a recording medium, and a program, and particularly to an apparatus and a method for information processing, a recording medium, and a program for establishing a broadband communication channel providing a high degree of privacy in data communication between a portable type information terminal apparatus such as a PDA (Personal Digital Assistant) and a server, for example.
FIG. 1 is a diagram showing an example of configuration of a related-art digital data communication system. In this digital data communication system, a radio communication network 3 is connected with a radio communication terminal apparatus 2 and a data communication server 4. The radio communication terminal apparatus 2 is connected with a PDA 1.
The PDA 1 is connectable to the radio communication terminal apparatus 2, and hence connectable to the data communication server 4 via the radio communication terminal apparatus 2 and the radio communication network 3. For example, the PDA 1 sends a request for delivery of data to the data communication server 4 via the radio communication terminal apparatus 2 and the radio communication network 3 on the basis of user operation, and receives the data delivered thereto from the data communication server 4 via the radio communication network 3. Also, the PDA 1 can transmit data recorded within the PDA 1 to the data communication server 4 via the radio communication terminal apparatus 2 and the radio communication network 3.
The radio communication network 3 is connected by radio to the radio communication terminal apparatus 2 such as a digital portable telephone or the like, or the data communication server 4 using a radio communication function of PHS (Personal Handyphone System) or W-CDMA (Wideband-Code Division Multiple Access), for example, and thereby performs data communication.
The data communication server 4 receives the request for delivery of the data transmitted thereto from the PDA 1 via the radio communication network 3, and then delivers (supplies) the corresponding data via the radio communication network 3. The data communication server 4 also receives the data transmitted thereto from the PDA 1 via the radio communication network 3.
A configuration of functions (modules) of the related-art digital data transmission system will next be described with reference to FIG. 2.
On the basis of an input signal from a GUT (Graphical User Interface) processing module 12, a data control module 11 of the PDA 1 controls data communication of a communication control module 13. The data control module 11 also controls data encryption processing or decryption processing of a cryptographic processing module 14 on the basis of an input signal from the GUT processing module 12.
When a user operates a GUT of the PDA 1, the GUT processing module 12 supplies an input signal for connection to the data communication server 4 to the data control module 11. Under control of the data control module 11, the communication control module 13 is connected to a communication control module 21 of the radio communication terminal apparatus 2. The cryptographic processing module 14 encrypts or decrypts data under control of the data control module 11.
The communication control module 21 of the radio communication terminal apparatus 2 is connected to the communication control module 13 of the PDA 1. The communication control module 21 is also connected to a communication control module 33 of the data communication server 4 via the radio communication network 3.
A data control module 31 of the data communication server 4 controls data encryption processing or decryption processing of a cryptographic processing module 32 and controls data communication of the communication control module 33. The data control module 31 also manages data exchanged in data communication.
The cryptographic processing module 32 encrypts or decrypts data under control of the data control module 31. The communication control module 33 is connected to the communication control module 21 of the radio communication terminal apparatus 2 via the radio communication network 3 under control of the data control module 31.
Related-art processing for the PDA 1 to transmit data to the data communication server 4 will next be described with reference to a flowchart of FIG. 3.
At a step S1, on the basis of an input signal (signal corresponding to an operation for being connected to the data communication server 4) supplied from the GUI processing module 12, the data control module 11 of the PDA 1 controls data communication of the communication control module 13. Under control of the data control module 11, the communication control module 13 establishes connection with the communication control module 21 of the radio communication terminal apparatus 2. At a step S11, the communication control module 21 of the radio communication terminal apparatus 2 establishes connection with the communication control module 13 of the PDA 1.
At a step S2, the communication control module 13 of the PDA 1 establishes connection with the radio communication network 3 via the communication control module 21 of the radio communication terminal apparatus 2. At a step S21, a base station not shown in the figure of the radio communication network 3 establishes connection with the PDA 1 via the communication control module 21 of the radio communication terminal apparatus 2.
At a step S3, the communication control module 13 of the PDA 1 establishes communication with the communication control module 33 of the data communication server 4 via the communication control module 21 of the radio communication terminal apparatus 2 and the radio communication network 3. At a step S31, the communication control module 33 of the data communication server 4 establishes communication with the communication control module 13 of the PDA 1 via the radio communication network 3 and the communication control module 21 of the radio communication terminal apparatus 2 under control of the data control module 31.
At a step S4, in order to prevent interception and falsification of data and the like, the data control module 11 of the PDA 1 controls the cryptographic processing module 14 so that the cryptographic processing module 14 encrypts transmission data. Then, the data control module 11 controls the communication control module 13 so that the communication control module 13 transmits the data encrypted by the cryptographic processing module 14 to the data communication server 4 via the radio communication terminal apparatus 2 and the radio communication network 3. At a step S32, the data control module 31 of the data communication server 4 controls the communication control module 33 so that the communication control module 33 receives the data transmitted by the PDA 1. The data control module 31 controls the cryptographic processing module 32 so that the cryptographic processing module 32 decrypts the encrypted data received by the communication control module 33.
At a step S5, the communication control module 13 of the PDA 1 is disconnected from the data communication server 4 under control of the data control module 11. At a step S33, the communication control module 33 of the data communication server 4 is disconnected from the PDA 1 under control of the data control module 31.
Thus, data communication between the PDA 1 and the data communication server 4 is performed through radio connection by PHS, W-CDMA or the like.
However, radio communication by PHS, W-CDMA or the like has a problem of a lower data transfer rate as compared with wire communication by optical fiber ADSL (Asymmetric Digital Subscriber Line) or the like or communication by satellite, which has recently been spreading, and a problem of a higher communication cost for each bit of transmission data even when the transfer rate is the same.
In addition, with the radio communication, a communication channel becomes unstable depending on conditions of radio waves, and therefore communication tends to be interrupted.
Furthermore, it is difficult to establish a broadband communication channel providing a high degree of privacy between a communication terminal apparatus such as a PDA with a limited processing capability and a server.